Winning over one or two customers in each of five or ten different segments—the consequence of taking a sales-driven approach—will create no word-of-mouth effect. Your customers may try to start a conversation about you, but there will be no one there to reinforce it. By contrast, winning four or five customers in one segment will create the desired effect.

Thus, the segment-targeting company can expect word-of-mouth leverage early in its crossing-the-chasm marketing effort, whereas the sales-driven company will get it much later, if at all. This lack of word of mouth, in turn, makes selling the product that much harder, thereby adding to the cost and unpredictability of sales.

— Crossing the Chasm, 3rd Edition: Marketing and Selling Disruptive Products to Mainstream Customers by Geoffrey A. Moore